Waves are one of the most enjoyable features of the the ocean. You can ride them, jump over them, dive under them, simply watch then gently roll in, or gasp as they crash and roar during a big swell.

Different conditions affect waves and it’s important to understand how the waves work, what types of waves may be present when you visit, and how you can deal with them to reduce the potential for injury.

Here's some top tips about the waves:

Waves
are generated by winds blowing across the ocean surface.

Waves
always break in generally shallow water.

Observe
and follow all safety warnings and signage.

If in
doubt, don’t go out.

So what are the waves?

Waves are a disturbance of the ocean
surface generally caused by the wind, though they can sometimes be caused by
undersea earthquakes and seismic events.

If you were to look at a wave from the
side, then you can see lots of different features of the waves like the
wavelength and wave height.

So where do the waves come from?

The biggest waves start from humble
beginnings. You may have noticed the birth of waves on a lake or pond, where a
gust of wind blows across the surface of the water creating little ripples
which dance along with the wind. These little ripples are sometimes
called cats paws and they are the absolute birth of a wave.
The longer they travel, and the stronger the wind, the bigger the wave gets.
The only thing that stops them from becoming big waves on a lake is that they
hit the other side of the lake before they can grow!

How do waves get so big?

There are three key factors that affect
the waves at the beach:

Wind Strength: the stronger the wind,
the bigger the swell.

Wind Direction: the wind needs to push the waves
towards the beach for there to be surf. Sometimes beaches are also protected by
headlands or reefs which stop waves from reaching the beach.

Wind
Duration or Fetch: the distance the wind has been blown over the
ocean. The bigger the fetch, the bigger and cleaner the surf will be.

Up until now, we’ve been discussing
swell as it travels through deep water. So what happens when the wave starts to
reach the shallow water? Why do different waves break slightly differently? Are
some waves more dangerous than others?

When the waves reach the coast...

The first thing that happens to a wave
as it approaches shallow water is that it slows down. If you imagine a set of
waves coming towards the beach as a line of runners all following each other,
when the first person slows down, everyone else bunches up as they all try not
to hit the person in front like an accordion! This process is called shoaling.

If one part of the wave reaches shallow
water before another, then the wave can appear to bend as one part slows down.
This can commonly be seen around headlands as the wave may wrap around to enter
a sheltered bay.

The breaking wave...

Finally, when the swell reaches shallow
water it pushes itself upward until the slope of the crest cannot support itself. This is when it will break. There are three types of breaking waves described by
surfers and lifesavers, each with their own key characteristics. On any beach, there will commonly be a combination of these three wave types breaking.

Spilling or rolling waves: are found
where there are generally flat shorelines. These are generally safer types of
waves. They occur when the crest breaks onto the wave face itself.

Plunging or dumping waves: create a
hollow tube when they break. Surfers call this the ‘barrel’ or ‘tube’..
Plunging waves are particularly dangerous as they can pick people up and ‘dump’
them onto shallow sandbanks or reefs with great force.

Surging Waves:may never actually break
as they approach the water’s edge since the water is very deep. They are
commonly seen around rock platforms and beaches with steep shorelines. They are
dangerous because they can appear suddenly and knock people over before
dragging them back into deeper water.

How does the heaviest wave in the world work?

Check out this amazing breakdown into
how the heaviest wave in the world works by the forecasting team at Surfline

What comes in, must go out...

When waves break in the shallow water of
a beach, called a sandbank, it pushes water towards the shoreline. If
the water didn’t recede back out to sea, it would build up, and up, and up
until we all lived in little Venice!

Fortunately, it does find a way to get
back out to sea by flowing into deeper channels in the surf zone. These
channels are called rip currents. Rip Currents and waves form an important
relationship in the surfzone; waves move water in, and rips move water out.
This is one of the most important concepts to understand to be able to ‘read’
the surf zone currents.

Check out this video that teaches you how
to spot a rip current. Watch out for the relationship between the waves and the rips: